Wrap-On 14175 175', Gray, Roof & Gutter Cable, Pre-Assembled, Designed For The Sole Purpose Of Preventing The Formation Of Ice Dams On Pitched Roofs With Non-Combustible Tab Shingles & In Metal Or Plastic Gutters & Downspouts, Provides Drainage Channels So That As Natural Thawing Occurs, Water Has A Path To Flow Off The Roof & Through The Gutters & Downspouts, Not For Use On A Flat Roof Nor Is It Intended To Clear The Roof Of Snow & Ice, Installation Is Simple, Can Be Used With Either Metal Or Plastic Gutters, Rated At 5W Per Foot, UL Listed.